The Simpson HSCNW1 High-Strength Coupler Nut with Witness Hole is built to create reliable, verifiable connections between threaded rods and anchor bolts in structural applications where tensile performance cannot be compromised. Engineered by Simpson to exceed the specified minimum tensile capacity of the corresponding bolts and threaded rod, this 1 in. rod diameter coupler nut gives contractors and engineers a straightforward way to join all-thread rod sections with confidence. The built-in positive stop promotes even thread engagement from both ends, and the distinctive Witness hole lets installers visually confirm full rod seating before a connection is finalized - eliminating guesswork at the point of installation.

Key Features

• Witness hole for visual installation verification - tighten each all-thread rod until it is visible through the Witness hole, giving installers on-the-spot confirmation that both rods are fully and correctly engaged before moving on
• Positive stop feature - ensures even, balanced thread engagement into each end of the nut, reducing the risk of uneven loading or under-threaded connections in critical structural joints
• Exceeds specified minimum tensile capacity - designed to out-perform the tensile requirements of the corresponding bolts and threaded rod, supporting use in high-strength structural assemblies where connection integrity is non-negotiable
• Compatible with non-hot-dip galvanized all-thread rod only - knowing the correct rod type upfront prevents costly compatibility mistakes on the job site and keeps the installation within engineered parameters
• Zinc plated or uncoated finish options - provides flexibility to match the corrosion-protection requirements of the surrounding assembly without sourcing a separate product

Why This Product

• Built-in quality assurance at every connection - the Witness hole is a practical, no-tool verification method that confirms proper rod installation without relying on torque feel alone, reducing the chance of under-engaged connections in structural rod assemblies
• Engineered for high-strength demand - because the coupler nut is designed to exceed the tensile capacity of the corresponding bolts and threaded rod, it is well-suited for load-critical connections where the coupler itself must never be the weak link
• Consistent, repeatable engagement every time - the positive stop eliminates the guesswork of how far to thread each rod, delivering uniform engagement depth from both ends and supporting predictable, code-consistent performance across multiple connections on the same project
• Trusted Simpson engineering for structural rod connections - designed specifically for connecting threaded rods to one another and to anchor bolts, the HSCNW series addresses a precise structural need with a purpose-built solution rather than a generic fastener adapted to the task

Specifications

• Manufacturer Part Number (MPN): HSCNW1
• Brand: Simpson Strong-Tie
• Series: HSCNW
• Rod / Bolt Diameter: 1 in.
• Height (Minimum): 2-1/2 in.
• Coating / Finish: Zinc Plated or Uncoated
• Compatible Rod Type: Non-hot-dip galvanized all-thread rod only
• Country of Origin: United States

Approved Applications

• Connecting threaded rods to one another in structural assemblies
• Connecting threaded rods to anchor bolts
• Applications requiring verified, full thread engagement via Witness hole inspection
• High-strength connections where tensile capacity must meet or exceed corresponding bolt and rod specifications

Options

• Available in standard strength and high strength depending on corresponding rod in use
• Couplers available with oversized threads on one end for installation on hot-dip galvanized bolts (See &OST models for ordering)
• OST couplers are typically oversized on one end of the coupler nut only and will be marked with an "O" on oversized side

Note: Product dimensions and/or screw

Frequently Asked Questions

What is the Witness hole on the HSCNW1, and how do I use it?

The Witness hole is a built-in opening in the coupler nut that provides a visual means to verify proper rod installation. When tightening two all-thread rods into the nut, you tighten each rod until it becomes visible through the Witness hole, confirming that both rods are fully and correctly engaged before finalizing the connection.

Is this coupler nut compatible with hot-dip galvanized all-thread rod?

No. The HSCNW1 is designed for use with non-hot-dip galvanized all-thread rod only. It should not be used with hot-dip galvanized all-thread rod.

What are the key dimensions of the HSCNW1?

The HSCNW1 is sized for a 1 in. rod diameter and has a minimum height of 2-1/2 in.

What finish options are available, and what is the strength rating of this coupler nut?

The HSCNW1 is available in either a zinc plated or uncoated finish. In terms of strength, the nut is designed to exceed the specified minimum tensile capacity of the corresponding bolts and threaded rod it is used with, making it suitable for demanding structural connections.